Praxis Agriculture (5701) Practice Exam

Alleles are the different variants of a gene. A gene is a specific DNA sequence that influences a trait, and variation in that sequence creates different forms that can be carried by individuals. Typically, an organism has two alleles for each gene, one inherited from each parent, which is why organisms are often described as having homozygous (same alleles) or heterozygous (different alleles) for that gene. Alleles can be dominant or recessive, shaping how traits appear in the phenotype. In agriculture, breeders look at different alleles for traits like disease resistance, yield, or flowering time to select superior varieties. The other terms—diploid, estrus, and gestation—do not describe gene variants: diploid refers to chromosome sets, while estrus and gestation relate to reproductive cycles and pregnancy.